Home, food & hobbies
729 everyday calculators for home, cooking and free time: recipes and servings, tips and shared bills, paint and flooring, pets, games and hobbies. Quick answers to the small questions of daily life, free in your browser.
Sous-vide water bath volume calculator
A tub filled 30 by 20 by 15 cm holds 9 liters; with 800 ml of bagged steaks inside, you pour 8.2 liters of water.
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Coffee beans from water volume calculator
500 ml of brew water at 1:16 needs 31.25 g of coffee beans. Enter your kettle volume and the ratio you brew with and get the dry dose in grams and ounces, plus…
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Oatmeal oats-to-liquid ratio calculator
Each oat cut drinks a different amount of liquid: 1 cup of rolled oats takes 2 cups of water or milk, steel-cut oats take four times their volume, and you also…
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Beer SRM color estimator
50 malt color units in a 5-gallon batch give an MCU of 10 and just over 7 SRM, an amber beer. Enter your grain bill's color units and the batch volume to place…
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Dessert quantity per person calculator
Ten guests need 15 dessert servings: the calculator plans 1.5 per person, enough for seconds without a second cake per guest, and rounds up to whole portions…
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Tea steeping temperature lookup
Green tea wants water at 80 °C (175 °F), gyokuro only 60 °C and black tea a full boil at 100 °C. Type the tea named on your tin and get the kettle temperature…
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Egg weight by size lookup
A large egg gives 50 g once the shell is off. Pick a USDA carton size, from peewee to jumbo, and get the average shelled weight in grams and ounces, together…
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Diffraction-limited aperture calculator
With 4.3 µm pixels and 550 nm light, diffraction starts to soften detail past f/6.3: enter pixel pitch and wavelength to find the smallest aperture worth using…
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Graduated ND filter transition calculator
A sky metering EV 15 over land at EV 12 means 3 stops of contrast and a 0.9 hard GND: enter both readings and the horizon to get the filter strength and where…
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Vertical angle of view calculator
A 50 mm lens on a 24 mm tall full-frame sensor sees about 27 degrees from top to bottom: enter the focal length and sensor height to check whether a facade or a…
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Guide number from aperture and distance
A correct exposure at f/8 with the flash 4.5 m away means a guide number of 36 at ISO 100: enter the aperture, distance and ISO of a shot that worked and get…
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ISO after stops change calculator
Raising ISO 100 by 2 stops multiplies sensitivity by 4 and lands on ISO 400: enter the starting ISO and a signed change in stops, whole or in thirds, to get the…
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Number of bars in a song calculator
A three-minute song at 120 BPM in 4/4 holds exactly 90 bars, each lasting 2 seconds. Enter the length, tempo and meter of any track to plan phrases, radio edits…
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Dotted note delay time calculator
At 120 BPM a dotted-eighth delay is 375 ms, with echoes landing at 750, 1125 and 1500 ms, between the straight beats.
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Interval in cents from frequency ratio calculator
A just fifth of 1.5 measures almost 2 cents more than the 700 cents of an equal-tempered fifth: enter any positive frequency ratio and see its size in cents…
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Knitting rows for length calculator
At 7.5 rows per inch, a 24-inch scarf takes 180 rows. Enter your row gauge, or the rows counted over 10 cm, and the finished length to get a whole-row count for…
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Knitting yarn yardage estimator
Multiply your stitch total by the yarn each stitch uses: 28000 stitches at 0.025 per stitch need 700 units of yarn.
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D&D armor class calculator
Studded leather with 16 Dexterity and a shield gives AC 17: a base of 12, plus 3 from Dexterity, plus 2 for the shield.
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D&D encounter XP budget calculator
Four level-5 characters have a Medium budget of 2000 XP; with 3 monsters the multiplier of 2 leaves 1000 XP of creatures to spend.
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D&D passive perception calculator
Wisdom +3 and a proficient +3 give a passive Perception of 16: 10, plus 3, plus 3. Add expertise, advantage or the Observant feat and see each term the Dungeon…
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Catan number pip dots calculator
A 6 or an 8 in Catan carries five pip dots: five of the 36 two-dice rolls pay that hex. Enter any token from 2 to 12 and see its odds, its twin token and its…
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Audio file size from sample rate
One minute of CD-quality stereo, 44,100 Hz at 16 bits, fills 10,584,044 bytes as a WAV file. Enter your sample rate, bit depth, channels and length to budget…
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Note from interval and root calculator
A perfect fifth above C is G, and a major third above F sharp is A sharp, not B flat: pick a root, an interval from unison to octave and a direction, and get…
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Vibrating string fundamental frequency
A string 1 m long at 100 N with 0.01 kg/m sounds at 50 Hz: enter the speaking length, tension and linear density of a guitar, violin or piano string and get its…
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Beads per length calculator
A 180 mm bracelet holds exactly 30 beads of 6 mm with nothing left over. Enter the finished length in mm, cm or inches, the bead size and any knots or clasp…
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Candle Wax Amount Calculator
Twelve 250 ml jars of wax at 0.9 g per ml need 2700 g, or 2.7 kg, for the whole batch. Enter one container's fill volume, your wax density and how many jars you…
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Macrame cord length calculator
A medium-density piece 80 long with 20 of fringe and 10 for the dowel needs 470 per working strand.
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Resin volume for mold calculator
A 20 by 10 by 2 cm cavity holds 400 ml; two of them filled to 90 % take 720 ml, or 777.6 ml once you add 8 % for cup residue.
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Darts Three-Dart Average Calculator
501 points scored with 15 darts is 33.4 points per dart and a three-dart average of 100.2: enter the points and the darts thrown to compare any match, leg or…
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Marathon Pace from Goal Time Calculator
Finishing a marathon in 3:30:00 means holding about 4:59 per kilometre, an average of 12.056 km/h.
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Tennis tiebreak score calculator
At 6–5 in a seven-point tiebreak, player A serves next, needs 1 point and player B needs 3. Enter both scores and who served first to keep the serve rotation…
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Maximum Operating Depth Calculator for Nitrox and Trimix
Nitrox with 32 % oxygen at a limit of 1.4 bar reaches its maximum operating depth at 33.75 m, shown conservatively as 33 m: enter the analyzed oxygen and your…
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Hiking time with elevation calculator
Ten kilometres with 600 m up and 300 m down take about 3 hours 10 minutes: 120 minutes of walking, 60 of climbing and 10 of descent.
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Rowing 500m Split Calculator for Distance and Time
Rowing 2000 m in 7:20 is a 1:50.0 split per 500 m. Enter the distance you covered and the elapsed time in seconds, minutes or hours, and compare long and short…
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Even-pace split times calculator
A 10 km race at 5:00 per kilometre gives ten identical laps and a 50:00 finish. Enter the distance, your target pace and the split interval, and get the…
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Climbing rope impact force calculator
A test-style fall at factor 1.77 with an 80 kg climber on a rope of 20 kN modulus peaks a little above 8 kN, more than 10 times body weight: enter fall factor…
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Household chore rotation calculator
Week 0 gives Alice the dishes, Bob the trash and Carol the vacuuming; each new week moves everyone one chore along, and after 3 weeks each person has done every…
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Gym cost per visit calculator
Monthly dues of 49.99 spread over 12 visits come to a little over 4 per workout. Add a join fee spread across the months you plan to stay, extras such as a…
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Weighted cost split calculator
Split 1000 by weights 2, 1 and 1 and the shares come out as 500, 250 and 250, or use percentages that add up to 100.
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Add time calculator
Add two durations in hours, minutes and seconds with the carries done for you: 1:45:40 plus 2:30:35 is 4:16:15, because extra minutes and seconds roll over at…
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Add hours to a time
Add hours to a time of day and get the new clock time plus the number of midnights crossed: 14:30 plus 5 hours is 19:30 the same day.
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Age calculator
Find someone's age in completed years between two dates: a person born on 1990-05-15 is 36 on 2026-07-25, because the birthday has already passed that year.
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Age in hours calculator
Turn an age in years into hours with one clear rule: each year counts as 365.25 days of 24 hours, so 1 year is 8,766 hours and 25 years is 219,150 hours.
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Age in seconds calculator
Find out how many seconds an age adds up to: each year counts as 365.25 days, so 25 years is 788,940,000 seconds.
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Age in years, months and days
Get a person's exact age as years, months and days: someone born on 1990-05-15 is 34 years, 3 months and 5 days old on 2024-08-20.
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Days until birthday
See how many days remain until the next birthday: for someone born on 1990-05-15, there are 294 days left on 2026-07-25, counting to the next birthday on…
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Appliance wattage calculator
See what an appliance really uses: a 1,500-watt heater run for 3 hours a day takes 4.5 kWh, and that energy times your price per kilowatt-hour is the daily…
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Baby age calculator
See your baby's age the way clinics count it: a baby born on 2025-01-15 is 79 weeks and 3 days old on 2026-07-25, which is also 18 months and 10 days.
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Balloon arch calculator
A 12-foot arch at 8 balloons per foot needs 96 balloons. Enter the arch length in feet and the density you want, and get a whole number to buy, rounded up so…
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Bathroom mirror size
A 36 × 34 inch vanity gets a mirror about 33.12 inches wide and 32.98 inches tall. Enter the vanity width and height in one unit, inches or centimetres, and get…
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Beauty product lasts calculator
A 50 ml serum used at 0.5 ml a day lasts 100 days, a little over three months. Enter the container size and your daily amount in the same unit, from millilitres…
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Bed size calculator
A 160 × 200 cm mattress covers 3.2 m² of floor, is labelled queen and sleeps two. Enter width and length in centimetres, metres, inches or feet to get the floor…
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Binge-watching calculator
Ten 45-minute episodes at 1.5× speed take 5 hours, a little over a fifth of a day. Enter the episodes left, how long each one runs and your playback speed to…
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Birth year calculator
Someone who is 35 in 2026 and has already had their birthday was born in 1991; before the birthday, one year earlier.
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Birthday weekday calculator
Someone born on 25 July 1990 has their 2026 birthday on a Saturday. Enter your birth date and the year you are planning to see which weekday the anniversary…
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Bold text
Type Hello world and get **Hello world**, ready to paste wherever Markdown bold is read, from chat apps to project notes.
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Bra size calculator
An 80 cm underbust with a 94 cm bust is a US 32DDD, a UK 32E and a European 80B. Enter both tape readings in centimetres or inches to get band and cup in all…
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Brake-specific fuel consumption calculator
An engine burning 10 kg of fuel per hour while delivering 50 kW at the shaft has a BSFC of 200 g/kWh.
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Calendar countdown
From 25 July 2026 to Christmas 2026 there are 153 days left. Enter today's date and the event date to get the signed number of calendar days: positive while it…
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Chronological age calculator
Someone born on 4 July 1985 is 40 years, 8 months and 16 days old on 20 March 2026. Enter a birth date and a reference date to get the calendar age that…
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